The overall objective and long term goal of the proposed research is to design, evaluate and improve methods for the systematic use of college student nonprofessionals in the mental health delivery system. This objective will be met primarily through assessment of the impact of the students working with individuals from four selected populations. The impact on each of the target populations will be assessed using multiple measures and multiple data sources, including attitudinal, behavioral, demographic, personality, and unobtrusive measurement indices. Over a three year span the project will develop selection and training procedures to answer the question of who works best with whom using what technique. The fundamental preventive effects of college students delivering mental health services on the social systems in which the target populations are embedded will be assessed through the use of non- equivalent control group and multiple time series designs. This portion of the research is based on the notion that if a service is truly effective as a preventive intervention it must not only demonstrate a change in the individuals served but in the relevant organizations, institutions and neighborhoods. For example, a program for children should have an impact on the school, the family and the peer group. Each of the above problems--target group change, selection and training, and social system change--are dealt with in the context of a systematic program for the efficient use of nonprofessional manpower.